As Internet technology develops, various Internet websites gain a broader understanding of user access information by exchanging the user data of visiting users among themselves. As a consequence, Internet websites can use collected user access information as a basis for providing users with products that better suit their needs.
In order for different Internet websites to be able to identify which collected user access information belongs to the same user, the various websites need to determine a unique identifier for each unique user and use the unique identifier as a basis for exchanging the user data of this particular user. In some conventional processes, when users visit various websites, requests may be sent to a central server to request unique identifiers for the users. The central server generates unique identifiers corresponding to the users based on user information included in the requests sent by the websites and sends these generated unique identifiers back to the various websites. The websites then write these unique identifiers into user client cookies. The websites then exchange user data on the basis of the unique identifiers.
In the processes described above, sometimes the central servers that generate unique identifiers corresponding to the users are operated by third parties, which could make the user information that is sent and/or received from the third party central servers vulnerable to security intrusions.